Unfortunately, it can be tough to determine if a book is considered scholarly because no one labels them as such (unlike journals. I have no idea why).
This is not a checklist. You need to weigh these criteria when deciding.
To determine if a book is considered scholarly or refereed, ask the following:
- Who is the author and what expertise do they have related to this topic?
- In most cases, that means they teach in academia.
- They may be involved in public policy in the government.
- Who is the publisher?
- Many publishers of scholarly material are affiliated with universities
- Some publishers are not, but you can learn more about the publisher's purpose by investigating what else they are publishing
- Who is the audience?
- Is this written for experts in the field, or a general audience?
- If something is written for an expert audience, it will include citations to research in academic journals, other scholarly books as well as data and statistics from authoritative sources.